PirB Expression And Regulation On Axon Growth In Murine RGCs

Adult central nervous system(CNS) have inadequate recover capacity after injury. This is mainly due to the unfriendly microenviromentaround injured sites. Many factors influence regeneration in this microenvironment,among them, inhibitory factors play pivotal roles in axon regeneration. Myelin-associated inhibitors(MAIs) and their receptors are the most representative members which limit axonal outgrowth. Three most important members, Nogo-A, MAG, and OMgp, have two common receptors: Ng R1 with its coreceptors[(p75(NTR), TROY, and Lingo-1]; and PirB. These proteins work together, activate signal pathway in neurons. Many intrinsic mechanisms are still left to be unveiled. Recent studies revealed that double blocking PirB and NgR leads to a near-complete discharge of myelin inhibition, which bring hope on neuroregeneration study in recent decades. Besides, the inhibitory molecules have others roles than axonal growth inhibition, such as neuroplasticity, development, and neurodegeneration. Thus, further investigation of these protein will be a great contributeto the whole neuroscience.Our study is divided into 3 parts:1. Confrim the exactly expression localization of PirB in RGCs; 2.investigating the time course of PirB expression in RGCs;3.investigating the mechanism of PirB regulating RGCs axon regeneration.Aim:To investigate the physiological function of PirB in the regeneration of RGCs axons.Method:In this study, we use primary cultured RGCs isolated from C57BL/6 mice as our object. We confirmed the expression of PirB in RGCs by immunofluorescent; we measured the mRNA and protein level of PirB and NgR by qPCR, RT-PCR and western blot; we knockdown PirB and/or NgR by transfecting RGCs with lentivirus and theeffect of the knockdown and CNTF treatment was evaluated by measuring the length of axons.Results and conclusions:1.PirB is expressed in RGCs, its expression pattern is fluctuant along with the differentiation process;2.Knocking down PirB showed partial promotion to the RGCs axon growth. However, knocking down NgR additionally did not improve the situation, and knocking down NgR alone had not effect on axon regeneration either.On the other hand, CNTF treatment had additional effect on PirB knockdown group.Our study supply novel experimental evidence for nerve injury.